package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否登录
 */
@Slf4j
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {

    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}",requestURI);

        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };

        boolean check = check(urls, requestURI);

        //判断不许要处理的请求直接放行
        if (check) {
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        //1-判断登录状态选择放行
        if (request.getSession().getAttribute("user") != null) {
            log.info("用户已登录,用户id为：{}",request.getSession().getAttribute("user"));
            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);
            filterChain.doFilter(request,response);
            return;
        }

        //2-判断登录状态选择放行
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录,用户id为：{}",request.getSession().getAttribute("employee"));
            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request,response);
            return;
        }

        log.info("用户未登录");
        //如果未登录则返回登陆结果，通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls,String requestURI){
        for (String url : urls){
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
